Roaming profile fails on two servers

We've got 12 terminal servers (XenApp 6 on 2008 R2) that are in a load-balanced pool, with users accessing the desktop. I have one user who can log into all servers, but when she logs into two of them, she gets a temporary profile. 

Here are the steps I've taken:

1. System properties -> profiles: When she's logged in, Windows reports that she has a roaming, temporary profile. When she logs out, there is no reference to the user
2. HKLM\Sofware\Microsoft\Windows NT\CurrentVersion\ProfileList: There is no reference to the user, nor are there any keys with .bak in the name
3. C:\users: There is no folder for the user, but there is a TEMP folder that she has NTFS rights to. I deleted the folder
4. I have verified that the user has NTFS rights on the roaming profile folder

When the user logs in, on the two impacted servers, we see event 1511 and 1521 in the Application log.

I'm not sure what else to check. Thoughts?

Thanks.